Allow user control on char-width of "ambiguous" characters

* src/character.c (syms_of_character) <ambiguous-width-chars>: New
char-table.

* lisp/international/characters.el (ambiguous-width-chars): Fill
the table.
(update-cjk-ambiguous-char-widths): New function.
(cjk-ambiguous-chars-are-wide): New defcustom, uses
'update-cjk-ambiguous-char-widths' as its :set function.
(use-cjk-char-width-table): Obey 'cjk-ambiguous-chars-are-wide' by
adding another child char-table for ambiguous-width characters,
where the width is set according to the option.

* lisp/language/chinese.el ("Chinese-GB", "Chinese-BIG5")
("Chinese-CNS", "Chinese-EUC-TW", "Chinese-GBK"):
* lisp/language/japanese.el ("Japanese"):
* lisp/language/korean.el ("Korean"): Add new language-info slot
'cjk-locale-symbol'.

Bug#64420

1 files changed, 8 insertions, 0 deletions

diff --git a/src/character.c b/src/character.c
index f4164360f21..2118b20a7c7 100644
--- a/src/character.c
+++ b/src/character.c
@@ -1117,6 +1117,14 @@ A char-table for width (columns) of each character.  */);
   char_table_set_range (Vchar_width_table, MAX_5_BYTE_CHAR + 1, MAX_CHAR,
                         make_fixnum (4));
 
+  DEFVAR_LISP ("ambiguous-width-chars", Vambiguous_width_chars,
+               doc: /*
+A char-table for characters whose width (columns) can be 1 or 2.
+
+The actual width depends on the language-environment and on the
+value of `cjk-ambiguous-chars-are-wide'.  */);
+  Vambiguous_width_chars = Fmake_char_table (Qnil, Qnil);
+
   DEFVAR_LISP ("printable-chars", Vprintable_chars,
                doc: /* A char-table for each printable character.  */);
   Vprintable_chars = Fmake_char_table (Qnil, Qnil);